How to Sharpen a Chainsaw

Dull chainsaws are slow—and dangerous

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Is your dull chainsaw blade burning and bucking its way through the wood? It's a slow way to cut. It's also a dangerous way to cut. Here's how to sharpen your chainsaw blade and cut more quickly.

Tools Required

  • Depth gauge guide for sharpening chain saw blades
  • Dremel tool
  • Dremel tool blade sharpening kit No. A679-02
  • File guide for sharpening chain saw blades
  • Flat file
  • Round file

Video: How to Sharpen a Chainsaw

A chainsaw’s nasty-looking cutters can scare you into thinking you can’t sharpen the saw yourself. But in about 10 minutes, with the help of a couple of inexpensive files and guides, you can transform your slow-cutting chainsaw into a firewood-cutting ninja. You can sharpen the chain right on the saw and right by the wood you’re cutting. Do it often, and you’ll get years of sharp cutting life from your chain. Here, we’ll show you how to use chain saw sharpeners.

A dull chainsaw blade can cause burning and buckling while sawing through wood, and it’s a slow and dangerous way to cut. Here are some lessons on how to use a chainsaw sharpener from The Family Handyman expert, Bob Tacke.

Project step-by-step (9)

Step 1

Check the Waste to See if it’s Time to Sharpen

  • Check the waste material from your saw cuts.
    • Pro tip: Dust means it’s time to sharpen. Chips indicate that the cutters are sharp. 
    • Note: A dull chain is dangerous—it greatly increases the chances of kickback. The chain is more likely to catch in the material and propel the bar up toward the operator. (Read Using a Chain Saw Safely, for more information).
    • Pro tip: Sharpening is easy if the cutters have dulled from normal use. If the cutters are nicked badly from accidental contact with rocks, dirt or objects embedded in trees, you may need to have the chain professionally sharpened or buy a new one.

Check the waste to tell if it's time to sharpen chainsaw

Step 2

Have the Right Tools on Hand

  • Buy four tools for freehand to use as a chainsaw sharpener:
    • A round file that matches the cutter diameter.
      • Note: Popular diameters for medium-duty chainsaws are 5/32, 3/16 and 7/32 inch. Check the owner’s manual for your saw’s requirements, or use the chain identification number stamped on the drive link. Small-engine dealers and hardware stores have charts to match this number with the right file diameter.
    • A file guide to hold the round file at a uniform depth as you sharpen each cutter.
    • A flat file.
    • A depth-gauge guide for resetting the depth gauges.
      • Pro tip: Don’t use a standard rattail file as a chainsaw sharpener. Its tapered diameter and coarse teeth will ruin your chain’s cutters.

chainsaw tools: depth gauge guide, flat file, round file, rattail file, file guide

Know Your Chain

Inspect the cutters (saw teeth) on your chain loop. The semicircular cutting edges can be quickly sharpened and reshaped with a round file. A depth-gauge fin in front of each cutter controls how deep the cutter bites into the wood. The angles ground on the cutters alternate between left and right to keep the saw cutting straight.

The cutters have semicircular cutting edges in specific diameters; to sharpen them, use a round file of the same diameter. In front of each cutter is a “depth gauge,” a piece of metal shaped like a shark fin. The depth gauge’s tip is a hair shorter than the tip of the cutter and controls how deep the cutter can bite. After repeated sharpenings, the cutters can become level with the depth gauges—and keep the saw from cutting. It’s easy to lower the depth gauges to the right height with a flat file and file guide.

three parts of the blade that get sharpened on chainsaw diagram